WHAT IS IT?
Biogas comes from wet organic waste. It’s a clean,
renewable resource that is safe for the environment. It
can replace fossil fuels and firewood to use for heating
WHERE DOES IT COME FROM?
As mentioned before, biogas comes from wet organic waste,
such as manure from livestock.
Cow manure actually contains 60% methane, which can be
used for energy instead of being emitted into the air.
WHAT’S AN ANAEROBIC DIGESTER?
Now, this is where the waste is treated. After the waste is
“harvested” from livestock pens it is taken to this tank
called an anaerobic digester. The methane is
concentrated for productive use while the sludge left
behind, full of nutrients, is used as an effective fertilizer
for the grass. The livestock eat the grass and it’s like a
THE PROCESS OF ANAEROBIC DIGESTION
There are three steps to anaerobic digestion…
1. Hydrolosis- polymers that can’t dissolve like
carbohydrates and cellulose are broken down
by bacteria and liquefied. They are hydrolised
into sugar which can then be decomposed into
CO2 and hydrogen. In this phase the gas levels
rise and the solid levels go down.
2. Acidogenesis- Acids formed in the last stage
are changed by acetogenic micro-organisms to
acetic acid. CO2 and hydrogen levels decrease.
3. Methanogenesis- Methane and CO2 are
produced from the acids in the acidogenic
phase. This is when the actual fuel shows up
with methanogenic bacteria that help break
down the biogas even further. It’s important in
this stage to mix the bacteria to move the
process along, so make sure the slurry is mixed
in as well.